The number keys, 1 through 9, are predefined hotkeys for showing the corresponding screen. Because the TD is constantly examining the current tournament conditions to determine what screen set and screen should be shown, after you select a specific screen to show it would immediately switch back to the screen it thinks should be shown due to tournament conditions. Therefore, when you select a specific screen to be displayed with the number keys, the screen lock is automatically engaged to keep that screen displayed. To allow the application to return to the automatic display of the appropriate screen, turn off the screen lock by pressing Ctrl+L. The Controls tab also has an Unlock Screen button (it toggles between Lock and Unlock), in the Screen section.